Friction clutch



22, 1950 w. v. THELANDER 2,519,414

FRICTION CLUTCH Original Filed March 22, 1946 a T 705 Ab 6 70b 55' flab 57 fggb \52 \L 55: 7 I 50 ii 55 I 124%? W30 7% Wlfzlza'eflif/zelwzakfl Patented Aug. 22, 1950 FRICTION CLUTCH W. :Vincent'Thelander, Auburn, :Ind., assignor .to Dana. Corporation,'-[Ioled0,iOhio, atcorporation of Virginia.

Original applicationMarchfiZ; 1946, Serial No. 656,327. Divided and this-application 'N0vem-- 'beeZS; 1-947,Serial'N0. 7823;477

10 ,Claims.

1 Thisapplication is. adivision oi my copending application Serial No. 656,327, filed March 22,. 19.46;

This .invention 1 relates to friction clutchesfor use on automobiles, tractors, andothcr vehicles; andgsuitable also; for industrial applications.

Inclutches-like that disclosediinmy Patent-No. 2,214,780,.issuedseptemberi'i, .1940, the pressure plate ismoved toward engagedpositicn bynovel spring-pressed release levers, and is moved toward-disengaged; position by springmeans acting betweenithe back-plate anddrive lugson the pressure plate. However, .these lugs projecting through openingsin the back;plate with a predetermined operating clearance caused an objectionable rattle unless special provisions were made tojeliminate the hammer-noise. In a copending application of Everson DeCour-sey and. myself, Serial'No. 611,049, we disclose the use of small wedge-shaped blocks, suitably mounted; on: the back plate inthe drive lug openings andaarranged to have abutment with the drive. lugs. on the coast side and normally urged inwardly with-respecttothe axis ofrotation of the'clutch bysuitable spring means so asto affordample working clearanoe'iorthe drive lugsin-the open.- ingsonly While these flying wedges are in retriacted position, the clearance being taken up automatically whcnthe flywheel attains; a predeterminedR. P. M., at which the. flying wedges. move outwardly under-centrifugal force against. theaction of the springrmeans.andxtakeupall clearance.

.Itzisthe: principal object .o'f my invention taprovide a. simpler andmore economical-and'more. practical construction, in which a single leaf" springspider-shaped element is provided between the radially inner portionof the back plate and thebackof the-pressure-plate, to assume drive torquewhen the "clutch is engaged, so thatthe lugs on the pressure plate, which heretofore causedtheobjectionable rattle by reasonpf contact with the sides of th openings in thehack plate, are kept moreor less centralized. with. respect to said openings, thereby eliminating rattling. According to the present invention, the. leaf spring spider element, besides assuming the; driving torquerand preventing the objectionable rattling; servesto exertthe springmressuraholding the pressure plate. enga ed, the-release; levers. being arranged to positively retract the pressurev plateinthedisengagement of the clutch.

Theinvention isillustratediinrthe accompanying drawing; in which- Fig. 1 is-arear view of a clutch embody ng mu invention, and

Figs. 2 and.3: are sectional details on1thezcorrespondingly numbered lines of Fig. 1.

The same reference numerals are appliedvto. corresponding partsthroughout the views.

Referring tothe drawing, the. clutch illustrated comprises. a pressure plate Hlb andback plate Mb. The latter has three equally circumferentially spaced attachingfiange portions 39, by] means of; which the back plate is fastened to the back. ofvv the flywheel, screws being entered through the holes.39' for that purpose. Only one of thethree flange portions39 is shown, the upper portion. of the figure being broken away to conserve space. in the, drawing, the other two flange portions being on the center lines varr-0 and a-d. The pressure plate Iiib cooperates in the .usual way With, a clutch disk (not shown) having the usual .fac ings for engagement with thefiat back face on the flywheel and the flat front face onthepressure. plate, the disk being: mounted in theusual wayyby means of ahub portion splined on the front-end ofa shaft constituting the driven element, and extending rearwardly from the clutch intothe "gear box of the transmission in the usual Way,- asdisclosed for example, in my earlier Patent No; 2.214 780.

"The present invention is particularly concerned with the leaf spring --means 22b; WhiChhOldS the pressureplate 135 in engaged position. The re;- lease=levers Me, of which'thereareithree on'the three center lines a-'b, a-c, antic-41, serve positively to retract thepressure plate. Each of'these levers ifs-preferably" connected by means of 'a crosspin. 5ll-at itsouter end toa lug 5i-projecting rearwardly from-thepressure plate, the'levers being fulcrumed intermediate their endsin openings E i-provided therefor'in plates 53-that are secured to'lugs Eestruckrearwardly fromthe web of'the back plate. 'Therelease levers are, 'ofcourse, opera-ted by a'throw-outcollarat their inner ends; The leaf spring means comprises cne-piece'leaf spring spider 22b interconnecting the'baclrplate and pressure-plateto assume drive torque and normally urge the pressure plate away from the back plate toward engaged position. Thespring. spider 22b'has'a perforated circular hub portion 55 which is riveted, as'indicated at 56, at circumferentially spaced points to the web of the back plate in concentric relation thereto and around the center hole-39*therein, and this spider has six radially projecting arms 5'! in equally circumierentiallyspaced relation which are arranged twobetween :each; pairaofadjacent release levers,

only four appearing in the drawing. The outer ends of the arms 5'! are fastened by screws 58 to the pressure plate, these screws being entered through holes in the end portions of the arms and threaded in registering holes provided in the pressure plate.

In operation, the spring spider 22b obviates the necessity for spring loading the release levers Ma, because it exerts the spring pressure itself holding the pressure plate [Sb engaged, the levers Ma being used only for positively disengaging the clutch. The spring spider 22b also serves to assume the drive torque, thereby giving the desired spring cushioned drive from the back plate 131) to the pressure plate Ifib, while maintaining the pressure plate accurately centered in relation to the back plate for smooth operation, and, inasmuch as the lugs 5| are kept more or less centered in relation to the openings in the back plate 131) and cannot come into contact with the sides of the openings, the objectionable rattling previously mentioned is eliminated. lhis construction is also of advantage in the shipment of the clutch assembiy, because the spider 23b ties the back plate i327 and pressure plate it?) together in a unitary assembly. That, of course, also facilitates installation. This clutch is obviously well ventilated, because the pressure plate lOb is exposed throughout the major portion of its circumference between those portions 39 of the back plate 13b that are attached to the flywheel, and the radially projecting arms 51 of the spring spider 221) are exposed also to a large extent between the attached portions 39 of the back plate.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. In a clutch, a back plate having a radially inner portion from which projects substantially radially a plurality of circumferentially spaced portions for attachment to a driving member, a ring-shaped pressure plate housed within the circumferentially spaced attaching portions of the back plate in radially outwardly spaced relation to the radially inner portion of said back plate and adapted to engage a driven member and engage it with the driving member, a plurality of clutch actuating levers mounted in circumferentially spaced relation on the radially projecting attaching portions of said back plate and operatively associated with the pressure plate to shift the same axially, and a single leaf spring spider comprising a central hub portion attached to the radially inner portion of said back plate and a plurality of outwardly reaching flexible arms integral with and supported by the hub portion at their inner ends and attached at their outer ends to the pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially in one direction.

2. In a clutch comprising a back plate attached to a driving member, a pressure plate housed within the back plate and adapted to engage a driven member and engage it with the driving member, a single leaf spring spider comprising a central hub portion attached to the back plate and a plurality of outwardly reaching flexible arms integral with and supported by the hub portion at their inner ends and attached at their outer ends to the pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially in a forward direction to engaged position, and clutch release lever means mounted on said back plate and operatively associated with said pressure plate to move the same rcarwardly to disengaged position.

3. In a clutch, a back plate having a radially inner portion from which projects substantially radially a plurality of circumferentially spaced portions for attachment to a driving member, a ring-shaped pressure plate housed within the circumferentially spaced attaching portions of the back plate in radially outwardly spaced relation to the radially inner portion of said back plate and adapted to engage a driven member and engage it with the driving member, flexible leaf spring means attached to said radially inner portion of said back plate and extending substantially radially outwardly and attached to said pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially away from the back plate to engaged position, and clutch release lever means mounted on said radially projecting attaching portions and operatively associated with said pressure plate to move the same toward the back plate to disengaged position.

4. In a clutch, a back plate having a radially inner portion from which projects substantially radially a plurality of circumferentially spaced portions for attachment to a driving member, a ring-shaped pressure plate housed within the circumferentially spaced attaching portions of the back plate in radially outwardly spaced relation to the radially inner portion of said back plate and adapted to engage a driven member and engage it with the driving member, a plurality of clutch actuating levers mounted in circumferentially spaced relation on the radially projecting attaching portions of said back plate and operatively associated with the pressure plate to retract the pressure plate to disengaged position, and a single leaf spring spider comprising a central hub portion attached to the radially inner portion of Said back plate and a plurality of outwardly reaching flexible arms integral with and supported by the hub portion at their inner ends and attached at their outer ends to the pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially away from the back plate to engaged position.

5. In a clutch comprising a back plate attached to a driving member, a pressure plate housed within the back plate and adapted to engage a driven member and engage it with the driving member, flexible leaf spring means radially disposed and attached at its radially inner portion to said back plate and at its radially outer portion to said pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially in a forward direction to engaged position, and clutch release lever means mounted on said back plate and operatively associated with said pressure plate to move the same rearwardly to disengaged position.

6. In a clutch comprising a back plate attached to a driving member, a pressure plate housed within the back plate and adapted to engage a driven member and engage it with the driving member, a single leaf spring spider comprising a central hub portion attached to the back plate and a plurality of outwardly reaching flexible arms integral with and supported by the hub portion at their inner ends and attached at their outer ends to the pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially in one direction, and clutch actuating levers mounted on the back plate and operatively associated with said pressure plate to move the same axially and accordingly determine engagement and dis engagement of the clutch.

7. In a clutch, a back plate having a radially inner portion from which projects substantially radially a plurality of equally circumferentially spaced portions for attachment to a driving member, a ring-shaped pressure plate housed within the circumferentially spaced attaching portions of the back plate in radially outwardly spaced relation to the radially inner portion of said back plate and adapted to engage a driven member and engage it with the driving member, a plurality of clutch actuating levers mounted in equally circumferentially spaced relation on the radially projecting attaching portions of said back plate and operatively associated with the pressure plate to shift the same axially, and a single leaf spring spider comprising a central hub portion attached to the radially inner portion of said back plate and a plurality of outwardly reaching flexible arms in equi-angular relationship integral with and supported by the hub portion at their inner ends and attached at their outer ends to the pressure plate between the attaching portions of said back plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially in one direction.

8. In a clutch comprising a back plate attached to a driving member, a pressure plate housed within the back plate and adapted to engage a driven member and engage it with the driving member, a single leaf spring spider comprising a central hub portion attached to the back plate and a plurality of outwardly reaching flexible arms integral with and supported by the hub portion at their inner ends in equi-angular relationship and attached at their outer ends to the pressure plate to transmit drive between said plates and maintain centered relationship therebetween while normally urging said pressure plate axially in a forward direction to engaged position, and clutch release lever means mounted on said back plate in equally circumferentially spaced relationship and between the arms of said spider and operatively associated with said pressure plate to move the same rearwardly to disengaged position.

9. In a clutch comprising a back plate and a pressure plate in concentric relation, a six-armed leaf spring spider mounted at its central portion on the central portion of the back plate and drivingly connected at the outer ends of the arms to the pressure plate at six equally circumferentially spaced points and arranged to urge the pressure plate axially in one direction, and three clutch release levers in equally circumferentially spaced relation, each midway between two adjacent spider arms, mounted on the back plate and operatively associated with the pressure plate to move the same axially and accordingly determine engagement and disengagement of the clutch.

10. In a clutch comprising a back plate and a pressure plate in concentric relation, a leaf spring for flexibly drivingly connecting the back plate and pressure plate comprising a central ringshaped hub portion adapted to receive fastening means for fastening the same to the back plate, and a plurality of outwardly reaching flexible arms integral with and supported by the hub portion at their inner ends and adapted to receive fastening means at their outer ends for fastening the same to the pressure plate, means for fastening the ring-shaped hub portion to the back plate and means for fastening the outer ends of said arms to the pressure plate.

W. VINCENT THELANDER.

REFERENCES CITED The following references are of record in the 

